Eccentric Mass Designs of Membrane-Type Acoustic Metamaterials to Improve Acoustic Performance

Abstract A deployment-scale array of locally resonant membrane-type acoustic metamaterials (MAMs) is fabricated. The acoustic performance of the array is measured in a transmission loss chamber, and a complex interaction between the individual cell and the array length scales is shown to exist. Transmission behavior of both the membrane and the array are independently studied using analytical models, and a method for estimating transmission loss through the structure that combines vibroacoustic predictions from both length scales is presented and shown to agree with measurements. Degradation of transmission loss performance often associated with scaling individual MAM cells into arrays is explained using analytical tools and verified using laser vibrometry. A novel design for hierarchical locally resonant acoustic metamaterials is introduced, and experimental and analytical data confirm this approach offers an effective strategy for minimizing or eliminating the efficiency losses associated with scaling MAM structures.

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An integrated design method for Membrane-type Acoustic Metamaterials

10.26678/abcm.diname2019.din2019-0041 ◽

2019 ◽

Author(s):

Lucas Yudi Moriya Sampaio ◽

Leopoldo de Oliveira

Keyword(s):

Design Method ◽

Integrated Design ◽

Acoustic Metamaterials ◽

Membrane Type

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Adjustable sound insulation frequency band through the combination of membrane-type acoustic metamaterial array

INTER-NOISE and NOISE-CON Congress and Conference Proceedings ◽

10.3397/in-2021-3472 ◽

2021 ◽

Vol 263 (1) ◽

pp. 5869-5877

Author(s):

Xiang Wu ◽

TengLong Jiang ◽

JianWang Shao ◽

GuoMing Deng ◽

Chang Jin

Keyword(s):

Thin Films ◽

Frequency Band ◽

Transmission Loss ◽

Structural Parameters ◽

Sound Insulation ◽

Acoustic Metamaterials ◽

Additional Mass ◽

Acoustic Metamaterial ◽

Material Parameters ◽

Membrane Type

Membrane-type acoustic metamaterials are thin films or plates composed of periodic units with small additional mass. A large number of studies have shown that these metamaterials exhibit tunable anti-resonance, and their transmission loss values are much higher than the corresponding quality laws. At present, most researches on membrane-type acoustic metamaterials focus on the unit cell, and the sound insulation frequency band can only be adjusted by adjusting the structural parameters and material parameters. In this paper, two kinds of acoustic metamaterials with different structures are designed, which are the center placement of the mass and the eccentric placement of the mass.The two structures have different sound insulation characteristics. By designing different array combinations of acoustic metamaterials, the sound insulation peaks of different frequency bands are obtained. This paper studies the corresponding combination law, and effectively realizes the adjustable sound insulation frequency band.

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